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41.
In signaling games the replicator dynamics does not almost always converge to states of perfect communication. A significant portion of the state space converges to components of Nash equilibria that characterize states of partial communication. Since these components consist of non-hyperbolic rest points, the significance of this result will depend on the dynamic behavior of specific perturbations of the replicator equations. In this paper we study selection-mutation dynamics of signaling games, which may be considered as one plausible perturbation of the replicator dynamics. We find that the long term behavior of the dynamics depends on the mutation rates of senders and receivers and on the relevance of communication. 相似文献
42.
Miguel Delibes-Mateos Pablo Ferreras Rafael Villafuerte 《Biodiversity and Conservation》2008,17(3):559-574
Over recent decades wild rabbit populations have undergone a sharp decline in Spain with consequent negative impact both on
a game-based economy, and on the conservation of threatened species that depend on rabbits. We investigated the relationships
between rabbit population change and habitat and game management in central-southern Spain. To determine recent rabbit population
changes we revisited 60 localities during summer 2002 to repeat surveys previously carried out in 1993. Each survey consisted
of 4-km walked transects to record indices of rabbit abundance. The percentage of vegetation cover and of different soil types
were also estimated during these transects. In the same areas, the type and intensity of game management practices were obtained
by interviewing hunting managers, hunters or gamekeepers. Rabbit populations were stable or increasing only in 26.6% of the
studied populations, more commonly in areas with soft soils where warren building is easier for rabbits and where rabbits
were an important game species and managed to increase their numbers. Although we could not establish causality, habitat management
and predator removal were the main management practices related to rabbit population change. Rabbit scarcity in Spain constitutes
a serious problem for conservation, so hunters, researchers and policy makers need to reach a consensus to establish a long-term
program to monitor rabbit population trends and share results obtained, especially when intense manage programs are being
carried out to improve rabbit abundance. 相似文献
43.
Devan Allen McGranahan 《Biodiversity and Conservation》2008,17(8):1965-1977
The private game industry has grown across Africa since the mid-20th century. While considerable research has documented wildlife
production on commercial land in many eastern and southern African countries, few studies have focused specifically on the
integration of livestock and game production in Namibia and Zambia. This paper reports a survey of 43 commercial conservancy
members in Namibia and 23 game farmers in Zambia conducted between September 2004 and June 2005. The survey was based on inductive
sampling theory and queried farmers on how they have integrated wildlife production into their management practices. Farmers
in each country reported considerable integration of wildlife conservation and agricultural production. Namibian farmers reported
substantial problems with bush encroachment, whereas none of their Zambian counterparts raised similar complaints. This paper
describes the state of rangeland management on commercial farms in Namibia and Zambia and identifies important areas where
further research can contribute to the enhancement of this conservation-production system. 相似文献
44.
We propose a variant of the discrete Lotka–Volterra model for predator–prey interactions. A detailed stability and numerical analysis of the model are presented to explore the long time behaviour as each of the control parameter is varied independently. We show how the condition for survival of the predator depends on the natural death rate of predator and the efficiency of predation. The model is found to support different dynamical regimes asymptotically including predator extinction, stable fixed point and limit cycle attractors for co-existence of predator and prey and more complex dynamics involving chaotic attractors. We are able to locate exactly the domain of chaos in the parameter plane using a dimensional analysis. 相似文献
45.
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47.
Ryo Oda Takuya Naganawa Shinsaku Yamauchi Noriko Yamagata Akiko Matsumoto-Oda 《Biology letters》2009,5(6):752-754
The identification of altruists based on non-verbal cues might offer a solution to the problem of subtle cheating. Previous studies have indicated that the ability to discriminate altruists from non-altruists emerges during evolution. However, behavioural differences with regard to social exchanges involving altruists and non-altruists have not been studied. We investigated differences in responses to videotaped altruists and non-altruists with the Faith Game. Participants tended to entrust real money to altruists more than to non-altruists, providing strong evidence that cognitive adaptations evolve as counter-strategies to subtle cheating. 相似文献
48.
49.
Gánti's chemoton model (Gánti, T., 2002. On the early evolution of biological periodicity. Cell. Biol. Int. 26, 729) is considered as an iconic example of a minimal protocell including three key subsystems: membrane, metabolism and information. The three subsystems are connected through stoichiometrical coupling which ensures the existence of a replication cycle for the chemoton. Our detailed exploration of a version of this model indicates that it displays a wide range of complex dynamics, from regularity to chaos. Here, we report the presence of a very rich set of dynamical patterns potentially displayed by a protocell as described by this implementation of a chemoton-like model. The implications for early cellular evolution and synthesis of artificial cells are discussed. 相似文献
50.
利用马尔萨斯(Malthus)增长定律对生命科学、国民经济以及银行信贷等方面的问题进行了系统分析,刻画出其复杂的非线性动力特征,给出了马尔萨斯定律解决实际问题的方法. 相似文献